My research group is invested in the discovery of phosphorus-based catalysts that make and break bonds via two-electron changes in formal oxidation state. By enforcing nontrigonal geometries on tricoordinate P(III) compounds, we attempt to create structural and electronic conditions that facilitate catalytic cycling in the P(III)⇌P(V) redox couple. This approach has resulted in the development of catalytic atom transfer and bond activation methods based on inexpensive, nonmetal phosphorus catalysts. The synthetic and mechanistic aspects of these reactions and their connection to other organophosphorus catalyzed methods will be described.